the format of GNSS data stream from smartphone's GNSS chipset used by Android/iPhone app are taking lists Android devices that support raw GNSS measurements as well as tools to log and analyze GNSS data. You can find the tools in the GPS Measurement Tools repo on GitHub, which includes the GNSS Logger APKand the GNSS Analysis app for Linux, Windows, macOS, and the Installation and User Manual.

Original equipment manufacturers (OEMs), developers, and researchers can make use of the tools in this page to test new phone designs, validate functionality, develop new algorithms, evaluate improvements to the GNSS system implementation as well as building value added apps.

Android devices that support raw GNSS measurements

Before you can get any raw GNSS output, you need to make sure that you have a device that can capture such data. Most devices manufactured in 2016 or later and shipped with Android 7.0 or higher provide raw GNSS data.

Depending on the device, raw GNSS measurements can include all or some of the following data:

• Pseudorange and pseudorange rate.
• Navigation messages.
• Accumulated delta range or carrier.
• Hardware (HW) clock.

collection using an Android Smartphone .GNSS shadow matching is a new positioning technique that determines position by comparing the measured signal availability and strength with predictions made using a 3D model. It complements conventional GNSS positioning and can significantly improve the cross-street positioning accuracy in dense the environments.

1. Suggestion: Why you are using external receiver/s to improve the positioning, I mean you can use built-in system to improve the solution. contact me for further help.

2. In your case, use Matlab, goGPS, GoogleEarthPro, GPS Track Editor, SBG Center or any other related live simulations where you can see each and every details you required.